West African countries have detained eight Chinese ships for fishing illegally and the boats' owners could be subject to millions of dollars in fines, environmental group Greenpeace and government officials said.
Inspectors from Guinea, Sierra Leone and Guinea-Bissau boarded the ships off their coasts which they found to be violating regulations on catching protected fish and using nets with small holes to facilitate bigger hauls.
The arrests came after a two-month regional patrol on a Greenpeace ship, the Esperanza which carried inspectors from the West African countries, in a bid to supplement national efforts, which are often hamstrung by budget and technology constraints.
West Africa has some the richest waters in the world, but stocks are being depleted as industrial trawlers, some operating illegally, comb the oceans from the seabed to the surface, Greenpeace says.
A study in the journal Frontiers in Marine Science estimated West Africa's annual losses from illegal and unregulated fishing at $2.3 billion.
The Esperanza patrol found 11 vessels in breach of regulations out of 37 stopped, and reported the breaches to local authorities who towed them back to port.
Two other foreign vessels were found to be non-compliant, including a European ship with shark fins aboard, and further investigations are under way, Greenpeace said.
"This is a surprisingly high amount of arrests, especially considering that the vessels knew about our patrols in advance," Greenpeace's Pavel Klinckhamers said on Tuesday.
Some of the ships have been released after paying fines. Others are still under investigation.
Chinese Foreign Ministry spokesman Geng Shuang said China consistently opposes all forms of illegal fishing, and demands that firms operate legally and protect the maritime environment.
"China hopes that the relevant countries can enforce the law in a civilised manner, handle it in accordance with the law and protect the legal rights of the relevant Chinese companies and their employees," Geng said.
An EU official in Dakar was not immediately available for comment. The EU, which imports around 874 million euros ($954 million) of fish products each year from West Africa, is subject to fishing quotas and pays compensation to local governments. It has also provided funding to crack down on illegal fishing.
Guinea's fishing minister, Andre Loua, confirmed the detentions and added that it needed more money and boats to effectively control illegal fishing.
Sierra Leone's Minister of Information Mohamed Bangura said three Chinese vessels had been detained and fines paid, without giving details. A Guinea-Bissau fishing official said fines were still being negotiated for some of the seized vessels.
($1 = 0.9164 euros)
(By Emma Farge; Additional reporting by Ben Blanchard, Saliou Samb, Umaru Fofana and Alberto Dabo; Editing by Matthew Mpoke Bigg and Robin Pomeroy)